TY - JOUR
T1 - Encouraged 6-min walking test indicates maximum sustainable exercise in COPD patients
AU - Casas, Alejandro
AU - Vilaro, Jordi
AU - Rabinovich, Roberta
AU - Mayer, Anamaria
AU - Barberà, Joan Albert
AU - Rodriguez-Roisin, Robert
AU - Roca, Josep
N1 - Funding Information:
Supported by grants FIS 00/0281 from the Fondo de Investigaciones Sanitarias; and Comissionat per a Universitats i Recerca de la Generalitat de Catalunya (1999 SGR 00228); and Red Respira C03/11.
Funding Information:
Alejandro Casas was a Pre-doctoral Research Fellow from Fundación Neumológica Colombiana (Colombia) supported by CHRONIC (IST-1999/12158) from the European Union; and, Anamaria Mayer was a Research Fellow from Federal University of Sao Paulo (Brasil) supported by CAPES and E-Remedy (IST-2000/25146).
PY - 2005/7
Y1 - 2005/7
N2 - Study objectives: In patients with moderate-to-severe COPD, an encouraged 6-min walking test (6MWT) is a high-intensity submaximal exercise protocol that shows an oxygen uptake (V̇O2) plateau after the third minute of the test. This last feature prompted the hypothesis that self-paced walking speed is set to achieve "maximal" sustainable V̇O2, namely "critical power" or "critical speed." Patients and methods: Eight patients with moderate-to-severe COPD (mean age, 68 ± 7 years [± SD]; FEV1,50 ± 13% predicted; PaO 2,69 ± 8 mm Hg) underwent the following tests on different days in order: (1) encouraged 6MWT; (2) standard incremental shuttle test to identify peak walking speed; (3) four different high-intensity, constant walking speed tests to exhaustion to calculate critical walking speed; and (4) timed walking test at critical walking speed (CWS) to examine sustainability of the exercise. Results: 6MWT and CWS showed similar results (mean of last 3 min): V̇O2 (1,605 ± 304 mL/min vs 1,584 ± 319 mL/min), minute ventilation (47 ±12 L/min vs 48 ± 11 L/min), respiratory exchange ratio (0.89 ± 0.1 vs 0.90 ± 0.1), heart rate (130 ± 18 beats/min vs 131 ± 16 beats/min), Borg dyspnea score (5.4 ± 1.3 vs 5.5 ± 2.4), and walking speed (1.49 ± 0.1 m/s vs 1.44 ± 0.1 m/s, respectively). Conclusion: This study supports that 6MWT indicates maximum sustainable exercise that might be related with its predictive value in COPD patients.
AB - Study objectives: In patients with moderate-to-severe COPD, an encouraged 6-min walking test (6MWT) is a high-intensity submaximal exercise protocol that shows an oxygen uptake (V̇O2) plateau after the third minute of the test. This last feature prompted the hypothesis that self-paced walking speed is set to achieve "maximal" sustainable V̇O2, namely "critical power" or "critical speed." Patients and methods: Eight patients with moderate-to-severe COPD (mean age, 68 ± 7 years [± SD]; FEV1,50 ± 13% predicted; PaO 2,69 ± 8 mm Hg) underwent the following tests on different days in order: (1) encouraged 6MWT; (2) standard incremental shuttle test to identify peak walking speed; (3) four different high-intensity, constant walking speed tests to exhaustion to calculate critical walking speed; and (4) timed walking test at critical walking speed (CWS) to examine sustainability of the exercise. Results: 6MWT and CWS showed similar results (mean of last 3 min): V̇O2 (1,605 ± 304 mL/min vs 1,584 ± 319 mL/min), minute ventilation (47 ±12 L/min vs 48 ± 11 L/min), respiratory exchange ratio (0.89 ± 0.1 vs 0.90 ± 0.1), heart rate (130 ± 18 beats/min vs 131 ± 16 beats/min), Borg dyspnea score (5.4 ± 1.3 vs 5.5 ± 2.4), and walking speed (1.49 ± 0.1 m/s vs 1.44 ± 0.1 m/s, respectively). Conclusion: This study supports that 6MWT indicates maximum sustainable exercise that might be related with its predictive value in COPD patients.
KW - 6-min walking test
KW - COPD
KW - Critical power
KW - Exercise testing
KW - Exercise tolerance
KW - Sustainable submaximal exercise
UR - http://www.scopus.com/inward/record.url?scp=22244471375&partnerID=8YFLogxK
U2 - 10.1378/chest.128.1.55
DO - 10.1378/chest.128.1.55
M3 - Article
C2 - 16002916
AN - SCOPUS:22244471375
SN - 0012-3692
VL - 128
SP - 55
EP - 61
JO - Chest
JF - Chest
IS - 1
ER -